Analysis For Collapse Process Of Multi-layer RC Frame Structures Under Earthquake

Multi-storey RC-frame structure occupies a large proportion of the building structure in ourcountry, the collapse of multi-storey frame structure in great earthquake is very serious, and it hasbecome a major threat to people’s life and property security, so research of the rule aboutstructural collapse and define the critical state of structural collapse accurately is necessary. Thispaper focuses on the rule of structural collapse, takes constant stiffness multi-layer RC-framestructure as the object of study, with height, span and number of floors as the variables, usesnonlinear finite element software ANSYS/LS-DYNA, bases on elasto-plastic time historyanalysis, studies the rule of plastic deformation’s development of constant stiffness multi-layerRC-frame structure, and the relationship between story-drift and structural collapse. The mainconclusions are as follows:(1) The paper proposes the concept about first domain model of damage and second domainmodel of damage.(2) The paper analyzed the appearance’s order of plastic hinge and the model of structuralcollapse.(3) The collapsed analysis of RC-frame structure with different height, different span anddifferent number of floors shows that higher story height and greater span will reduce theintegrity and the energy dissipation capacity of structure, but appropriately increasing number offloors is good for the collapse resistance of structure.(4) Through the shaking table simulation test of seven frame structure, the article finds the1/50in GB and1/40in ASCE/SEI about story-drift are just an essential condition for thestructural collapse, but not a sufficient condition. This paper considers defining the critical stateof structural collapse as when the substructure turns to variable institutions.